The second reason is that rockets can carry more satellites more easily — and cheaply — than ever before. Rather, satellites have gotten smaller thanks to the electronics revolution. The majority of these satellites are used for observing Earth or for communications and internet. With a goal of bringing the internet to underserved areas of the globe, two private companies, Starlink by SpaceX and OneWeb together launched almost 1, smallsats in alone.
With the huge growth in satellites, fears of a crowded sky are starting to come true. A day after SpaceX launched its first 60 Starlink satellites, astronomers began to see them blocking out the stars. Experts have been studying and discussing the potential problems posed by these constellations and ways the satellite companies could address them. These include reducing the number and brightness of satellites, sharing their location and supporting better image-processing software.
This is the zone where the ISS orbits and where the space shuttle used to do its work. In fact, all human missions except for the Apollo flights to the moon took place in this zone. Most satellites also work in this zone. Geostationary or geosynchronous orbit is the best spot for communications satellites to use, however.
This is a zone above Earth's equator at an altitude of 35, km 22, mi. At this altitude, the rate of "fall" around the Earth is about the same as Earth's rotation, which allows the satellite to stay above the same spot on Earth almost constantly.
The satellite thus keeps a perpetual connection with a fixed antenna on the ground, allowing for reliable communications. When geostationary satellites reach the end of their life, protocol dictates they're moved out of the way for a new satellite to take their place.
That's because there is only so much room, or so many "slots" in that orbit, to allow the satellites to operate without interference. While some satellites are best used around the equator, others are better suited to more polar orbits — those that circle the Earth from pole to pole so that their coverage zones include the north and south poles.
Examples of polar-orbiting satellites include weather satellites and reconnaissance satellites. There are an estimated half-million artificial objects in Earth orbit today , ranging in size from paint flecks up to full-fledged satellites — each traveling at speeds of thousands of miles an hour.
Only a fraction of these satellites are useable, meaning that there is a lot of "space junk" floating around out there. With everything that is lobbed into orbit, the chance of a collision increases. Space agencies have to consider orbital trajectories carefully when launching something into space. Agencies such as the United States Space Surveillance Network keep an eye on orbital debris from the ground, and alert NASA and other entities if an errant piece is in danger of hitting something vital.
This means that from time to time, the ISS needs to perform evasive maneuvers to get out of the way. Collisions still occur, however. One of the biggest culprits of space debris was the leftovers of a anti-satellite test performed by the Chinese, which generated debris that destroyed a Russian satellite in Also that year, the Iridium 33 and Cosmos satellites smashed into each other, generating a cloud of debris.
NASA, the European Space Agency and many other entities are considering measures to reduce the amount of orbital debris.
Some suggest bringing down dead satellites in some way , perhaps using a net or air bursts to disturb the debris from its orbit and bring it closer to Earth.
Others are thinking about refueling dead satellites for reuse, a technology that has been demonstrated robotically on the ISS. Most planets in our solar system have natural satellites, which we also call moons. For example, Hyperion produces spectral bands which enabled us to better characterized minerals. China and Brazil unite in a joint quintuple mission to monitor everything from agriculture, environment, water pollution and urban planning in their respective countries.
PROBA is a micro, cube-looking satellite with meter hyperspectral data. Using its dextrous viewing angles, the PROBA satellite produced the world-renowned global vegetation archive. Worldview imagery is so sharp that you can almost see license plates. Planetscope is low cost, light weight and low orbit from the company called Planet.
This orchestra of micro satellites nicknamed doves orbit the Earth in concert scanning at meter resolution images. Image Credit: Planet. In fact, it was the first commercial satellite that was granted a license in America. QuickBird is versatile and cost effective delivering optical imagery at 60cm. But in , it was decommissioned and no longer serves the community. Image credit: ISRO. Also known as Arirang, this optical satellite provides 1-meter resolution imagery. RapidEye originated in Germany.
Then, BlackBridge purchased it. Despite several owners, this 5-satellite constellation provides 5-meter resolution anywhere at least daily. Pleiades consists of 2 nimble satellites operating in the same orbit. The Indian cartography series of commercial satellites collect land information with multispectral, panchromatic and stereo mapping capabilities.
DMC masters disaster monitoring with its highly responsive, humanitarian constellation. SkySat is the type of gadget James Bond uses to spy on super-villains. All rights reserved. TRMM examines at cloud structure and precipitation mostly at the equator. GOES knows weather. NOAA satellites enable us to get a complete view of weather and environmental conditions around the world each day. Meteosat is the geostationary observer in Europe and Africa.
A smaller number of satellites turn their "eyes" toward space, where they capture magnificent vistas of stars, planets and galaxies and scan for objects, such as asteroids or comets, that could be heading for a collision course with Earth.
Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Prev NEXT. Space Exploration. You're looking at the world's first geosynchronous satellite, Syncom I.
Unfortunately, it stopped sending signals just seconds before it got comfortable in its orbit.
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